Details for: BPIFB1

Gene ID: 92747

Gene Type:  Protein-coding  - A gene that serves as a template for producing a messenger RNA (mRNA) molecule, which is then translated into a functional protein.

Symbol: BPIFB1

Ensembl ID: ENSG00000125999

Description: BPI fold containing family B member 1

Selected Context(s):  Overall

Cell Significance Landscape

Contexts:

Associated with

Significant Cells

Cell Significance Index (CSI) scores for the chosen context(s)

  • nasal mucosa goblet cell CL0002480
    CSI 50.27
    rCSI 58.3%
    PRS 99.08
  • epithelial cell of lower respiratory tract CL0002632
    CSI 46.65
    rCSI 36.16%
    PRS 99.81
  • secretory cell CL0000151
    CSI 39.93
    rCSI 41.66%
    PRS 99.41
  • mucus secreting cell CL0000319
    CSI 39.44
    rCSI 62.64%
    PRS 99.76
  • multi-ciliated epithelial cell CL0005012
    CSI 33.34
    rCSI 33.27%
    PRS 98.54
  • duct epithelial cell CL0000068
    CSI 33.21
    rCSI 48.59%
    PRS 99.86
  • goblet cell CL0000160
    CSI 32.5
    rCSI 30.71%
    PRS 99.34
  • tracheal goblet cell CL1000329
    CSI 31.56
    rCSI 68.91%
    PRS 99.63
  • acinar cell CL0000622
    CSI 31.41
    rCSI 46.05%
    PRS 99.76
  • club cell CL0000158
    CSI 26.29
    rCSI 38.51%
    PRS 99.55
  • mucous neck cell CL0000651
    CSI 21.37
    rCSI 30.8%
    PRS 99.35
  • deuterosomal cell CL4033044
    CSI 19.08
    rCSI 64.49%
    PRS 97.71
  • bronchial goblet cell CL1000312
    CSI 18.04
    rCSI 72.1%
    PRS 99.89
  • tracheobronchial serous cell CL0019001
    CSI 15.65
    rCSI 67.63%
    PRS 99.68
  • lung ciliated cell CL1000271
    CSI 13.18
    rCSI 15.24%
    PRS 98.57
  • serous secreting cell CL0000313
    CSI 12.82
    rCSI 64.84%
    PRS 99.73
  • airway submucosal gland duct basal cell CL4033024
    CSI 12.4
    rCSI 79.33%
    PRS 99.9
  • lung secretory cell CL1000272
    CSI 12.17
    rCSI 30.13%
    PRS 99.79
  • respiratory basal cell CL0002633
    CSI 12.15
    rCSI 12.59%
    PRS 99.75
  • serous secreting cell of bronchus submucosal gland CL4033005
    CSI 12.14
    rCSI 69.1%
    PRS 99.27
  • pulmonary ionocyte CL0017000
    CSI 11.32
    rCSI 13.78%
    PRS 99.5
  • ciliated cell CL0000064
    CSI 10.66
    rCSI 17.26%
    PRS 97.91
  • ionocyte CL0005006
    CSI 10.65
    rCSI 11.42%
    PRS 99.45
  • respiratory suprabasal cell CL4033048
    CSI 8.76
    rCSI 11.23%
    PRS 99.79
  • squamous epithelial cell CL0000076
    CSI 8.05
    rCSI 19.11%
    PRS 97.88
  • foveolar cell of stomach CL0002179
    CSI 7.86
    rCSI 16.74%
    PRS 99.49
  • lung goblet cell CL1000143
    CSI 7.56
    rCSI 84.55%
    PRS 100
  • stratified epithelial cell CL0000079
    CSI 7.13
    rCSI 44.01%
    PRS 99.04
  • respiratory goblet cell CL0002370
    CSI 5.92
    rCSI 64.45%
    PRS 99.9
  • ciliated columnar cell of tracheobronchial tree CL0002145
    CSI 5.75
    rCSI 13.1%
    PRS 97.9
  • myoepithelial cell CL0000185
    CSI 5.72
    rCSI 14.48%
    PRS 99.73
  • bronchus fibroblast of lung CL2000093
    CSI 5.72
    rCSI 4.65%
    PRS 99.6
  • tracheobronchial goblet cell CL0019003
    CSI 4.54
    rCSI 73.02%
    PRS 100
  • stem cell CL0000034
    CSI 3.89
    rCSI 3.75%
    PRS 99.38
  • lung neuroendocrine cell CL1000223
    CSI 3.01
    rCSI 4.46%
    PRS 99.07
  • basal cell of epithelium of trachea CL1000348
    CSI 1.02
    rCSI 7.22%
    PRS 99.78

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this specific cell.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.
Network Configuration

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  • Query Gene
  • Node Color (Target Cell CSI, relative to current network):
    • Very High
    • High
    • Medium
    • Low
    • Very Low
    • CSI N/A
  • Node Size: Proportional to Target Cell CSI magnitude
  • STRING PPI Edge
  • Shared Pathway Edge (ONTOLOGY)

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Other Information

This section provides additional information about the gene, including a description generated by an AI language model and details about associated proteins.

## Summary [BPIFB1](/details-gene/92747) (BPI fold containing family B member 1), also known as LPLUNC1, is a protein-coding gene located on chromosome 20q11.21. It is a member of the BPI-fold containing protein family, which is strongly associated with innate immunity and host defense. Functional annotations indicate that [BPIFB1](/details-gene/92747) is a secreted protein involved in the [innate immune response in mucosa](/details-ontology/GO:0002227) and acts as an antimicrobial peptide ([R-HSA-6803157](https://reactome.org/content/detail/R-HSA-6803157)). Expression data reveals its highly specific and abundant presence in secretory and epithelial cells of the respiratory tract, with top significance in [nasal mucosa goblet cell](/details-cell/CL0002480) and [epithelial cell of lower respiratory tract](/details-cell/CL0002632). This localization is consistent with its proposed role as a first-line defense protein at mucosal surfaces ([Link](https://doi.org/10.1093/hmg/11.8.937)). ## Cellular Roles and Expression Landscape The expression profile of [BPIFB1](/details-gene/92747) firmly establishes its role as a key protein in the mucosal tissues of the respiratory system. **Overall**, the gene shows the highest significance in a range of specialized secretory and epithelial cell types responsible for maintaining the airway barrier. The most significant expression is observed in [nasal mucosa goblet cell](/details-cell/CL0002480) (CSI: 50.27), [epithelial cell of lower respiratory tract](/details-cell/CL0002632) (CSI: 46.65), and other [secretory cell](/details-cell/CL0000151) subtypes such as [mucus secreting cell](/details-cell/CL0000319) and [club cell](/details-cell/CL0000158). Its high significance extends to various [goblet cell](/details-cell/CL0000160) populations, including those in the trachea and bronchus, as well as glandular cells like [acinar cell](/details-cell/CL0000622). Furthermore, its notable presence in [multi-ciliated epithelial cell](/details-cell/CL0005012) and [lung ciliated cell](/details-cell/CL1000271) suggests a potential role in the mucociliary clearance apparatus. This highly restricted expression pattern within the airway epithelium underscores its specialized function in local host defense. ## Pathways and Molecular Function The molecular functions of [BPIFB1](/details-gene/92747) are deeply integrated with the [Innate immune system](/details-pathway/R-HSA-168249). As a secreted protein found in the [extracellular region](/details-ontology/GO:0005576) and within [extracellular exosome](/details-ontology/GO:0070062), its primary annotated role is as an [antimicrobial peptide](/details-pathway/R-HSA-6803157). This function is likely mediated through its capacity for [lipid binding](/details-ontology/GO:0008289), a common mechanism for BPI family members to disrupt microbial membranes. Beyond direct antimicrobial activity, [BPIFB1](/details-gene/92747) is also implicated in immunomodulation. It is annotated with the biological process of [negative regulation of toll-like receptor 4 signaling pathway](/details-ontology/GO:0034144), suggesting that it may help control and resolve inflammation in response to bacterial components like lipopolysaccharide (LPS). This dual function as both a microbicidal and an immunomodulatory agent positions [BPIFB1](/details-gene/92747) as a critical regulator of homeostasis at the mucosal interface. Research has demonstrated its ability to modulate immune responses to pathogens such as *Vibrio cholerae* ([Link](https://doi.org/10.1093/infdis/jir544)). ## Research Directions The specific localization and function of [BPIFB1](/details-gene/92747) suggest it is a key component of respiratory mucosal defense, offering several avenues for future investigation. **Proposed Hypotheses:** 1. [BPIFB1](/details-gene/92747) directly neutralizes common respiratory bacterial and viral pathogens through its lipid-binding activity, thereby preventing colonization and infection of the airway epithelium. Its high concentration in mucus may serve as a primary barrier against inhaled microbes. 2. In addition to its antimicrobial properties, [BPIFB1](/details-gene/92747) acts as a key immunomodulatory factor in the airways, preventing excessive inflammation during infection by dampening TLR4-mediated signaling in epithelial and resident immune cells. Dysregulation or deficiency of [BPIFB1](/details-gene/92747) could contribute to the pathology of chronic inflammatory airway diseases like asthma or COPD. **Key Experimental Approach:** To test the hypothesis that [BPIFB1](/details-gene/92747) modulates airway inflammation (Hypothesis 2), an *in vitro* co-culture experiment could be designed. Primary human bronchial epithelial cells could be cultured at an air-liquid interface to promote differentiation into a mucociliary epithelium. These cultures could then be transfected with siRNA to knock down [BPIFB1](/details-gene/92747) expression or treated with exogenous recombinant [BPIFB1](/details-gene/92747) protein. Following this, the cells would be challenged with LPS, a potent TLR4 agonist. The resulting inflammatory response could be quantified by measuring the secretion of pro-inflammatory cytokines (e.g., IL-6, IL-8, TNF-alpha) via ELISA and analyzing the activation of the NF-kB signaling pathway through western blotting for phosphorylated p65. A significant increase in inflammation in the knockdown group or a decrease in the recombinant protein treatment group would support its role as a negative regulator of TLR4 signaling in the respiratory tract. **Therapeutic Potential:** Given its role as a secreted, natural defense molecule specific to the airways, [BPIFB1](/details-gene/92747) presents considerable therapeutic potential. A strategy based on **activation** or supplementation, rather than inhibition, would be appropriate. Recombinant [BPIFB1](/details-gene/92747) could be developed as an inhaled biologic agent. This could be used to augment mucosal defenses in individuals with compromised immune systems or those suffering from chronic respiratory infections, such as patients with cystic fibrosis or bronchiectasis. Its potential to both fight microbes and dampen inflammation makes it a particularly attractive candidate for diseases characterized by a vicious cycle of infection and inflammation.

Genular Protein ID: 3091970409

Symbol: BPIB1_HUMAN

Name: BPI fold-containing family B member 1

UniProtKB Accession Codes:

Q8TDL5 A8K2H8 Q5QP43 Q6UWY1 Q6ZRU7 Q96HK6 Q9BQP8 Q9BWZ6 Q9H4V6

Database IDs:

AGR 1 AlphaFoldDB 1 Antibodypedia 1 Bgee 1 BioGRID 1 BioGRID-ORCS 1 BioMuta 1 CCDS 1 CDD 2 CPTAC 1 CTD 1 ChiTaRS 1 DMDM 1 DNASU 1 DisGeNET 1 EMBL 7 Ensembl 1 ExpressionAtlas 1 GO 5 GeneCards 1 GeneTree 1 GenomeRNAi 1 GlyConnect 1 GlyCosmos 1 GlyGen 1 HGNC 1 HOGENOM 1 HPA 1 InParanoid 1 IntAct 1 InterPro 4 KEGG 1 MANE-Select 1 MINT 1 MassIVE 1 NCBI Taxonomy 1 OMA 1 OpenTargets 1 OrthoDB 1 PANTHER 2 PIRSF 1 PRIDE 1 PRO 1 PathwayCommons 1 PaxDb 1 PeptideAtlas 1 Pfam 2 PharmGKB 1 Pharos 1 PhosphoSitePlus 1 PhylomeDB 1 Proteomes 1 ProteomicsDB 2 RNAct 1 Reactome 1 RefSeq 1 SMART 1 SMR 1 STRING 1 SUPFAM 1 SignaLink 1 TopDownProteomics 1 TreeFam 1 UCSC 1 VEuPathDB 1 eggNOG 1 iPTMnet 1 jPOST 1 neXtProt 1

Citations:

PubMed ID: 11971875

Title: PLUNC: a novel family of candidate host defence proteins expressed in the upper airways and nasopharynx.

PubMed ID: 11971875

DOI: 10.1093/hmg/11.8.937

PubMed ID: 12975309

Title: The secreted protein discovery initiative (SPDI), a large-scale effort to identify novel human secreted and transmembrane proteins: a bioinformatics assessment.

PubMed ID: 12975309

DOI: 10.1101/gr.1293003

PubMed ID: 14702039

Title: Complete sequencing and characterization of 21,243 full-length human cDNAs.

PubMed ID: 14702039

DOI: 10.1038/ng1285

PubMed ID: 11780052

Title: The DNA sequence and comparative analysis of human chromosome 20.

PubMed ID: 11780052

DOI: 10.1038/414865a

PubMed ID: 15489334

Title: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

PubMed ID: 15489334

DOI: 10.1101/gr.2596504

PubMed ID: 21900486

Title: LPLUNC1 modulates innate immune responses to Vibrio cholerae.

PubMed ID: 21900486

DOI: 10.1093/infdis/jir544

Sequence Information:

  • Length: 484
  • Mass: 52442
  • Checksum: A32A85F74D544E81
  • Sequence:
    • MAGPWTFTLL CGLLAATLIQ ATLSPTAVLI LGPKVIKEKL TQELKDHNAT SILQQLPLLS 
AMREKPAGGI PVLGSLVNTV LKHIIWLKVI TANILQLQVK PSANDQELLV KIPLDMVAGF 
NTPLVKTIVE FHMTTEAQAT IRMDTSASGP TRLVLSDCAT SHGSLRIQLL HKLSFLVNAL 
AKQVMNLLVP SLPNLVKNQL CPVIEASFNG MYADLLQLVK VPISLSIDRL EFDLLYPAIK 
GDTIQLYLGA KLLDSQGKVT KWFNNSAASL TMPTLDNIPF SLIVSQDVVK AAVAAVLSPE 
EFMVLLDSVL PESAHRLKSS IGLINEKAAD KLGSTQIVKI LTQDTPEFFI DQGHAKVAQL 
IVLEVFPSSE ALRPLFTLGI EASSEAQFYT KGDQLILNLN NISSDRIQLM NSGIGWFQPD 
VLKNIITEII HSILLPNQNG KLRSGVPVSL VKALGFEAAE SSLTKDALVL TPASLWKPSS 
PVSQ